Animals can die of starvation. There are maggots coming out of them. People are shooting them, putting knives in their throats, doing horrific things and these past few years nobody has really been doing anything.

Jessie Miller

Men are the only animals that devote themselves, day in and day out, to making one another unhappy. It is an art like any other. Its virtuosi are called altruists.

Many times I am asked why the suffering of animals should call forth more sympathy from me than the suffering of human beings; why I work in this direction of charitable work more than toward any other. My answer is that because I believe that this work includes all the education and lines of reform which are needed to make a perfect circle of peace and goodwill about the Earth.

All birds, even those of the same species are not alike, and it is the same with animals as with human beings.
The reason Wakantanka does not make two birds, or two animals, or humans exactly alike is because each is placed here by Wakantanka to be an independent individuality and to rely on its self.

Shooter Teton Sioux

Man is an animal which, alone among the animals, refuses to be satisfied by the fulfilment of animal desires.

To be nonviolent to human beings and to be a killer or enemy of the poor animals is Satan's philosophy. In this age there is always enmity against poor animals, and therefore the poor creatures are always anxious. The reaction of the poor animals is being forced on human society, and therefore there is always strain of cold or hot war between men, individually, collectively or nationally.

A. C. Bhaktivedanta Swami Prabhupada

Various philosophers and religious leaders tried to convince their disciples and followers that animals are nothing more than machines without a soul, without feelings. However, anyone who has ever lived with an animal--be it a dog, a bird, or even a mouse--knows that this theory is a brazen lie, invented to justify cruelty.

Those who, by their purchases, require animals to be killed have no right to be shielded from the slaughterhouse or any other aspect of the production of the meat they buy. If it is distasteful for humans to think about, what can it be like for the animals to experience it?

Peter Singer

There is no fundamental difference between man and the higher animals in their mental faculties... The lower animals, like man, manifestly feel pleasure and pain, happiness, and misery.